1. Field of the Invention
The present invention relates generally to deployable antenna reflector structures. More particularly, the present invention relates to an improved antenna reflector structure that provides a reduced number of components without compromising mechanical stability or deployment reliability.
2. Discussion of the Related Art
In the field of space exploration, large structures must often be foldable in order to fit into launch vehicles having limited cargo capacity. Once in space, these structures must deploy to a size sufficiently large to justify the cost of launching them. A typical such structure is a large aperture antenna reflector. Current deployable antenna reflector structures are quite complex with large numbers of truss elements having varying sizes and varying designs. For example, antenna reflector deployment typically requires the pivoting of truss elements around multiple axes that point in multiple directions. This complexity causes the manufacture of a single antenna reflector to be very costly due to time consuming assembly and high component costs. Current antenna reflector structures are also not very adaptable to multiple applications.
A substantial reason for such complicated antenna reflector designs has been the need to achieve a sufficient level of mechanical stability as well as deployment reliability. Mechanical stability has typically been achieved through box truss hoops or multiple triangular configurations--both requiring three-dimensional element designs with multiple components. Deployment reliability has been achieved through complex synchronization mechanisms or solenoid operated latch arrangements--both requiring additional weight and cost. Deployment reliability also depends on the method of mesh stowing and deployment.
The large number of components also causes current antenna reflector structures to be extremely heavy, which reduces the launch vehicle cargo capacity and reduces the stowed natural frequency. The stowed natural frequency is significant because launch vibrations matching the natural frequency or one of its harmonics may cause substantial damage to the antenna reflector. Thus, there is a need to combat the problem created by complex antenna reflector structure designs without compromising mechanical stability or deployment reliability.